Erickson worries that underground nuclear tests could occur again, but not the open-air tests that led to cancer downwind in Utah. Congress later apologized for those tests and created a compensation fund for some downwind cancer victims.

While underground tests are safer, they have been known to vent through the surface and spread radiation downwind.

The Times of London, however, quoted unnamed British defense officials saying they figured they would need to develop new warheads without full nuclear testing because of the Comprehensive Test Ban Treaty. They said they instead likely would have to depend on "subcritical" tests coupled with analysis by supercomputers.

The Times quoted one official saying, "We got to build something that we can never test and be absolutely confident that when we use it, it will work."

The Times also reported that some critics in Britain charge that the program will breach the Nuclear Non-Proliferation Treaty.

---

E-mail: leei@desnews.com